Sulphurized lubricating oil



Patented Aug. 27, 1940 PATENT OFFlCE SULPHURIZED LUBRICATING OIL Marcellus T. Flaxman, Wilmington, Calif., as-

signor to Union Oil Company of California, Los Angeles, Calif., a corporation of California No Drawing. Application September 20, 1937, Serial No. 164,704

1 4 Claims.

This invention relates to the preparation of sulphurized oils particularly sulphurized petroleum lubricating oils, and the primary object is to provide a sulphur-oil base which will be stable,

5 may be incorporated readily either in substantial proportions to produce extreme pressure lubricants or the like or in very small proportions to overcome corrosion tendencies which exist in certain typesof lubricating oils, and will not cause the products to turn black during manufacture or storage.-

Briefiy stated the invention resides in a sulphurized vegetable oil known as jojoba oil. The invention also resides in mineral lubricating oils containing gizater or lesser proportions of sulphurized jojoba oil, including additions of 10% for example, or more or less, in the preparation of extieme pressure transmission lubricants, as well as the addition of from to 2% to very 2o highly solvent refined highly parafiinic lubricating oils to overcome tendencies thereof to corrode certain types of hearings in internal combustion engines.

Jojoba (hd-hfr-ba) oil is a vegetable oil practically free from glycerides which is obtained from the jojoba seed as by pressing. The jojoba seeds are borne by a small shrub or tree, Simmondsia californica, family Buxaceae, of Southwest North America, and probably elsewhere including parts of the orient. The jojoba oil used for the present invention is obtained on the market under the designation of raw or crude jojoba oil, which apparently has been merely pressed from the seeds and filtered. The oil is freely fluid at ordinary temperatures, and is largely in the nature of a liquid wax, being a mixture of higher alcohols and esters. A typical oil has a mild odor, an acid number of practically 0, an iodine number of 80, and a saponification number of 85 to 95. The sulphurized oil is readily prepared by heating it moderately (e. g. at 350 F. or within a range of 300 F. to 400 F. for example) with flowers of sulphur until the oil takes up a sulphur content of about 16% more or less. In 5 general a maximum of about 16% sulphur combines with the oil, but more may be added where free sulphuris desired. Similarly much smaller quantities may be combined according to requirements, for example 5% or even less. This procedure involves merely heating jojoba oil with the sulphur for a period of an hour, more or less, until the sulphur has been taken up by the oil. It is of course to be understood that sulphurization may also be accomplished by any of the well known commercial procedures, as by the addition of sulphur chloride at ordinary temperatures.

In the preparation of transmission lubricanr and other extreme pressure lubricants, any mineral lubricating oil appropriate for the purpose 5 will have, for example, 10% of the above mentioned sulphurized product blended therewith. Obviously greater or lesser percentages of the sulphurized jojoba oil may be introduced according to the purpose and the functions to be per- 10 formed. Thus, in transmission lubri ants, the proportion may be varied between 59 and 25% or more, especially according to the s phur content of the jojoba oil and the amount oil permissible or desirable in the product. 16

When adding the sulphurized jojoba oil to lubricating oils for internal combustion engines or the like, asmaller percentage may be relied upon as a corrosion inhibitor and possibly will also impart some wear resisting properties. ample between about 0.5% and 1.5% of sulphurized jojoba oil containing between about 10% and 20% of sulphur may be added to a heavily solvent extracted, highly paraffinic lubricating oil to overcome a tendency of such un- 25 modified heavily treated lubricating oil to corrode certain kinds of bearings such as cadmiumsilver bearings used in recent years in some types of internal combustion engines. Thiswill yield for example a total sulphur content of from so about 0.05% to 0.5% based on the combined mineral and jojoba oil. This small percentage of sulphurized oil effectively overcomes or materially reduces such corrosive tendencies. Also it has been found that the addition of about 10% of 35 the sulphurized jojoba oil, containing from 10% to 20% sulphur, or for example about 16% sulphur, to a lubricating oil will increase the film strength very greatly.

Inv the preparation of lubricants especially suitable for use in hypoid gear sets, I incorporate considerably more sulphur in the jojoba oil than when I expect to use the sulphurized jojoba oil in extreme pressure lubricants of the mild type. In fact, for use in hypoid lubricants, I employ an excess of sulphur over that which can be absorbed without giving a product corrosive to copper. For example, I may add as much as 30% or more of sulphur to the jojoba oil where extreme antiseizing properties, as in cutting oils 5 or hypoid lubricants, are required. While the exact theory is not clear, it appears that a portion of this larger amount of sulphur is held in the form of polysulphides which readily liberate active sulphur at the instant that extreme 55 For ex- 20 antiseizing properties are required. This may be added in amount to yield a total sulphur content, for example as much as 5% or 6% sulphur. To improve the lubrication obtained with highly sulphurized jojoba oil I may also add 1% to 10% of an oil-soluble soap such as lead naphthenate.

As indicative of the improved film strength imparted to lubricating oils by the use of the sulphurized jojoba oil of this invention the following tests on the S. A. E. extreme pressure lubricant testing machine are given. In the case of an S. A. E. grade of mineral lubricating oil testing about pounds at 400 R. P. M. on the S. A. E. machine, such a lubricating oil containing 10% of sulphurized jojoba oil containing 12% of sulphur, tested 210 pounds at 400 R. P M. and pounds at 750 R. P. M. A hypoid type of lubricant consisting of the same base oil and 10% of sulphurized jojoba oil containing 24% of sulphur tested 550 pounds at both 400 R. P. M. and 750 R. P. M., 550 pounds being the limit of the machine. In other words the lubricating oil containing 10% of the 24% sulphurized jojoba oil rates as a full hypoid lubricant. For a description of the S. A. E. extreme pressure lubricant testing machine and the method of testing, reference is made to the S. A. E. Journal or S. A. E. Transactions for July 1936, pages 293 to 296, being volume 31 of the Transactions and volume 39 of the Journal.

All of these oils have a red or reddish hue which is distinct from the characteristic black of ordinary sulphurized oils.

It is to be understood that the above disclosures are furnished as merely illustrative of the generic invention here disclosed and not as limiting except as defined by the appended claims.

I claim:

1. A lubricating oil comprising a mineral oil and an appreciable proportion of sulphurized jojoba oil in which elemental sulphur has been combined to sulphurize the oil.

2. A lubricant comprising mineral lubricating oil and from to 20% of jojoba oil containing combined sulphur in an amount between about 10% and 20%.

3. A mineral lubricating oil comprising a heavstituent jojoba oil ily solvent extracted highly parafilnic mineral lubricating oil containing between about /g% and 2% of sulphurized jojoba oil in which elemental sulphur has been combined to sulphurize the oil.

4. A mineral lubricating oil containing between about 0.5% and 20% of sulphurized jojoba oil in which elemental sulphur has been combined to sulphurize the oil.

5. A lubricant comprising mineral lubricating oil and less than about 25% of sulphurized jojoba oil to impart a sulphur content to the lubricant between about 0.05% sulphur and 6.0% sulphur, the product being of reddish hue and substantially free from blackening tendencies.

6. A lubricant comprising mineral lubricating oil and less than about 20% of sulphurized jojoba oil imparting a sulphur content to the total composition between about 0.05% and 0.5%.

7. A lubricant according to claim 5 containing a soap.

8. A lubricant according to claim 5 containing between about 1% and 10% of lead naphthenate.

9. A lubricating oil according to claim 1 which is reddish in hue and free from substantial tendency to blacken during manufacture and storage.

10. A hypoid lubricant comprising a mineral lubricating oil and a quantity of sulphurized jojoba oil imparting a total sulphur content between about 1% and 6%.

11. A lubricant comprising as an essential concombined with substantial amounts of elementary sulphur sufiicient to impart corrosion reducing characteristics and improved film strength.

12. A lubricant comprising mineral oil and jojoba oil combined with elementary sulphur in proportions sufilcient to impart extreme pressure and corrosion inhibiting characteristics.

13. A lubricant comprising jojoba. oil with which an appreciable proportion of elemental sulphur has been combined, the product being of reddish hue and substantially free from black.- ening tendencies.

14. A lubricant comprising jojoba oil with which from 10% to 30% of elementalsulphur has been combined, the product being of reddish hue and substantially free from blackening tendencies.

MARCELLUS T. FLAXMAN. 

